This invention relates generally to an apparatus and method for maintaining a controlled environment. More particularly, the invention relates to an energy efficient dehumidifier which may be used alone or in connection with passive cooling systems to maintain a comfortable environment more efficiently.
In America the use of air conditioning is common place and considered by most to be a necessity. A significant portion of the energy use in America is consumed by air conditioning.
This was of little concern to America during the period of cheap energy costs. However, this ended with the era of the oil embargo and it is believed to be generally accepted that the days of cheap energy are gone forever.
The large amounts of energy used by America have placed a financial strain on the economy particularly with regard to the balance of payments and is viewed by many as even a greater threat to America. The large dependence upon imported oil still remains even though the source of supply of imported oil is volatile and cannot be guaranteed. The high cost of oil from OPEC has resulted in some conservation. Thermostats have been lowered in winter and raised in the summer to attempt to produce energy consumption. A great deal of work is also being performed in the area of passive cooling to provide comfortable controlled environments with low energy costs.
Passive cooling, however, cannot reliably remove humidity from the air because the cooling does not ordinarily reach the dew point temperature. Accordingly, although passive cooling can provide temperatures in the comfortable range, these temperatures may not be satisfactory in conditions of high humidity. Dehumidification is therefore required.
Commercially available room air dehumidifiers are relatively inefficient and conventional air conditioners waste considerable energy if only dehumidification is desired by providing cooling not only redundant with but actually detrimental to the passive cooling system. The air conditioning can make the environment uncomfortable by unnecessarily reducing the temperature in order to remove humidity which significantly affects the comfort in the environment.
The problem of providing dehumidified air to a controlled environment is well known. Known methods of doing this are shown in U.S. Pat. Nos. 2,715,320, 3,293,874, 3,460,353, 3,921,413 and 4,189,929. Since a source of heat is readily available in conventional air conditioning units, one need only provide a heating coil in connection with the cooling coil so that the air which has been produced to the dew point temperature to provide dehumidification is heated to a desired temperature before entering the room. While this type of system is workable it does not increase the efficiency of the apparatus. Rather, it provides the desired results at a similar cost to conventional air conditioning.
It is also well known in the art that heat exchangers can be utilized in connection with ventilating and heating systems. Examples of such heat exchangers are shown in U.S. Pat. Nos. 1,825,498, 2,092,835, 2,945,680, 4,194,538, 4,222,436. These devices usually include a means for bringing in fresh outside air and transferring heat from the exhausted inside air to the incoming outside air to reduce the heat loss.
With the large increases in the cost of energy, a need has arisen for a highly efficient apparatus and method for providing a comfortable controlled environment. Much of this effort has apparently been directed to increase the efficiency of conventional air conditioning systems. While this has reduced energy consumption, it has not provided an answer to the problem. It is believed that the present invention prides a solution to the long felt need for an efficient apparatus and method for controlling environments. The apparatus and method of the invention feels this long felt need for providing an efficient and workable solution to controlling environments. Other objects of the invention will become apparent from the following detailed description in the specification.